Commitments And Contingencies (Narrative) (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Schedule Of Commitments And Contingencies [Line Items]
Loss Contingency Accrual	$ 39
Loss Contingency, Range of Possible Loss, Portion Not Accrued	$ 50
Document Period End Date	Mar. 31, 2017
Purchase obligation over the next twelve months	$ 5,200
Other Receivables	277	$ 331
Realogy [Member]
Schedule Of Commitments And Contingencies [Line Items]
Other Receivables	41
Wyndham [Member]
Schedule Of Commitments And Contingencies [Line Items]
Other Receivables	$ 25